Historically, engine lubricating oil efficiencies have been bolstered at the production level by the introduction of specific additives to the virgin oil. Engine oil is basically contaminated and degraded by the following: a) engine piston(s) blow-by (undesirable bi-products of engine combustion, a portion of which escapes past the pistons and piston rings into the crankcase) comprising fuel soot, partially burned and unburned fuel, steam and various gases and acids; b) foreign liquids, abrasive silicones (dirt), engine component wear particles and oil oxidation by-products; c) the emulsification of the foreign liquids with chemical elements common to the oil e.g., sulfur combines with liquids and elevated engine temperatures to produce corrosive sulfuric acid. The only form of management afforded to the oil in this hostile environment is the physical inclusion of an oil filter. Although the oil filter is effective in removing solids from the oil, its inability to remove dilutants such as moisture and acids leaves oil vulnerable to viscosity breakdown and eventual loss of lubricity. Further, filters that become plugged with sludge and other solids, force the filter by-pass valve to open, allowing unfiltered oil to circulate to downstream engine components. Thus a primary cycle of undue engine wear and over contamination of oil commences. Problems generated are diverse in nature, however of major concern in this instance is increased cylinder bore and piston ring wear. Consequently, the percentage of piston blow-by increases impacting a heavier than normal contaminant load upon the crankcase oil which accelerates degradation. The problem has now gone full cycle. Crankcase pressures increase accordingly and can force oil past engine gaskets and seals. The condition also facilitates the ejection of oil from the engine crankcase via the aspiration conduit fouling the air cleaner, culminating in elevated carbon monoxide emissions. Also oil is vented along with the contaminated crankcase emission vapours, migrating via the PCV system and engine intake manifold en route to the engine combustion chambers, adversely fouling the combustion process. Again, this results in undue component related wear and a higher percentage of piston blow-by entering the crankcase. Relevant PCV problems will be referred to later in this document. This phenomena continues to compound itself with every engine revolution. Increased fuel consumption; loss of engine power; elevated exhaust emissions and a host of other engine operating problems result. An additional compounding factor is the human element, and is a real world problem, in that many owner/operators do not regularly change their engine oil and filter as per OEM specified. They simply top-up the engine oil, sometimes to excess. Resultant problems are similar in nature to the aforementioned.
It has now been the law for approximately 40 years that crankcase emissions from internal combustion engines must be recirculated back to the engine's air-fuel induction system for recombustion in the piston chambers. The return flow of the emissions is normally through the oil return lines extending between the crankcase and the engine's valve or cam covers, and from the valve or cam covers through an external hose or tube to the engine's intake manifold where the emissions are blended with the air-fuel mixture from the carburetor/fuel injectors (in normally aspirated engines) for delivery to the combustion chambers. A positive crankcase ventilation (PCV) valve controls the flow of crankcase emissions into the fuel-air induction system, normally in response to engine running speeds.
The PCV (Positive Crankcase Ventilation) valve is usually located in one of three engine locations: 1) at the engine crankcase vent in the valve/cam covers; 2) in line with the return conduit; or 3) screwed directly into the engine intake manifold. The valve meters and blends the flow of contaminated crankcase emissions into the engines air/fuel delivery system (intake manifold) in response to existing negative pressures within the manifold at various engine load requirements. The path of the emissions from the crankcase via the PCV valve/system, intake manifold and combustion chamber (where they undergo a change of state) and partially re-enter the crankcase as piston blow-by, is the secondary engine cycle of wear and contamination. The PCV valve is also intended to arrest a dangerous back flow condition to the crankcase that could arise as a result of an engine intake manifold backfire. This could cause a crankcase explosion.
The source and nature of crankcase emissions is well known and need not be discussed in further detail. Suffice is to say that in addition to unburned and partially burned fuel and volatile gases that are desirably recycled for combustion, the emissions also include a number of entrained contaminants that, even if combusted, are harmful to the engine or the environment or both. To the extent that the contaminants are combusted, they are exhausted from the engine as harmful pollutants. On the way in and out of the engines combustion chamber(s) they impair the function of critical engine components including critical emission controls such as the oxygen sensor and catalytic converter(s). To the extent that the contaminants are not combusted, they simply remain in the engine, for example as efficiency destroying combustion chamber deposits, jamming piston rings open, hindering their function or they partially return to the crankcase where they contaminate the oil as previously mentioned. As a consequence, this culminates in a loss of lubricating efficiency, sludge build-ups and a host of other problems that degrade engine performance, increase fuel consumption, elevate exhaust emissions and shorten engine life. These problems increase cumulatively over time and are the result of the second cycle of wear and contamination originating within the engine crankcase. The first cycle exiting the crankcase via the oil filter by-pass valve and, the second exiting via the Crankcase vent and PCV valve/system.
Prior art inventions involving superseded carburetted engines have made a variety of attempts to recycle combustible volatile matter in crankcase emissions through insertion of various PCV system filtering devices, without also recycling the entrained contaminants. Varying degrees of success were achieved in this theatre of operations. However, due to their disposition between the PCV valve and the engine intake manifold, many of these inventions have been impractical and commercially unsuccessful. This was due primarily to imbalances that arose to the design calibrations of the intake manifold (air/fuel induction system) by their devices. This had the adverse affect of increasing the cubic capacity of the manifold, externally, which subsequently generated imbalances to the air/fuel ratios, of which the manifold is synergistic. As a consequence, either fuel efficiency or exhaust emissions or both were compromised. As previously stated, some devices attained limited success on older generation carburetted engines, and the technology of the day utilized in the static measurement of such fuel efficiency and exhaust emissions supported this. However, in today's high-tech world and with the availability of vastly advanced and sophisticated test models, procedures and measuring equipment e.g., Environmental Protection Agency and the Federal Test Procedure (EPA/FTP), which subjects the engine to a variety of driving and load conditions on a chassis dynamometer for testing, and is the only full and acceptable standard for measuring true engine performance in relation to the subject matter, indicate otherwise. Further, when attempts have been made to apply this class of older technology to 'state of the art modern day computer controlled engines, they have been found to compromise OEM related fuel and exhaust emission efficiencies. The engine's oxygen sensor, located in the exhaust manifold, detects the additional air from the prior art devices and consequently additional fuel is injected into the intake manifold to counter the imbalance.
For example, Bush in U.S. Pat. No. 4,089,309, describes an open crankcase emission device that requires the use of an auxiliary air intake structure 43 that draws outside ambient air into the device for initial cooling of crankcase emissions. This introduces uncalibrated oxygen into the PCV system which, as previously indicated, is detected by the oxygen sensor utilized in today's computerized engine management systems and causes the system to inject fuel that is surplus to requirement. Bush, in a later U.S. Pat. No. 4,370,971, abandons the previous system configuration in favour of repositioning the system between the PCV valve 27 and the intake manifold entry port 36. In doing so, Bush not only retains the auxiliary air intake structure 69 with attendant problems but also subjects the whole configuration to a negative pressure environment. This, claims Bush, relates to improvements in the control of crankcase emissions, without due concern to the detrimental affects on the intake manifold design and operation. Specifically, Bush's later configuration now in direct communication with the interior of the engine intake manifold and unbalances the manifold calibrations by externally increasing its cubic capacity. This avails additional oxygen to and unbalances the stoichiometric air/fuel mixture within the manifold. Again, this condition is detected by the engine's oxygen sensor, and further confuses the computer which can only respond by injecting additional fuel to counter the imbalance. Even therefore if Bush removed and plugged the auxiliary air intake structure 69 to accommodate modern-day engines, his system's disposition would still fail it.
A similar approach is taught by Costello in U.S. Pat. No. 5,190,018 to that of Bush in U.S. Pat. No. 4,370,971. Costello's device is similar in structure, operation and disposition to that of Bush, with all the attendant disadvantages, including creating an uncalibrated increase in the volume of the engine's intake manifold.